1. Field of the Invention
This invention relates to a torque steering angle sensor that can detect a steering torque and a steering angle of a steering wheel of a vehicle and a method for correcting the same.
2. Description of the Related Art
Conventionally, electric power assisted steering device for vehicles is provided with a torque sensor which can detect a steering torque. Such a torque sensor can detect a steering angle as well as the steering torque (See e.g. JP-A-2014-66561).
The torque steering angle sensor is configured so as to detect a steering torque by detecting a torsional angle of a torsion bar coupling an input shaft and an output shaft of a steering shaft. For example, the torsional angle of the torsion bar, that is a steering torque can be detected by arranging a circular ring magnet that is provided with a plurality of different magnetic poles having different polarities in a circumferential direction around an input shaft and magnetic path forming members that are configured so as to vary a relative angle between a ring magnet depending on the twist of the torsion bar and vary a transmitting magnetic flux by varying a positional relation with the magnetic poles depending on a variation of the relative angle. The magnetic path forming members are made of, for example, a magnetic material such as permalloy material.
On the other hand, a steering angle can be detected by detecting a rotational angle of the input shaft and the output shaft. For example, a magnetic field detecting element is arranged opposite the ring magnet of the input shaft. The present applicant proposes that to detect a number of a rotation of the ring magnet by arranging a slide magnet that varies a length between a magnet field detecting element for detecting a steering angle depending on a rotation of a ring magnet and detecting a magnetic field variety from the slide magnet.